Electric switch



April 8, 1933. M. P. LUTHER ELECTRIC SWITCH Filed April 2, 1930 3 Sheets-Sheet 1 mum JiZJewr- MART/IV R LUTHER Q g w April 18, 1933. p LUTHER 1,903,824

ELECTRIC SWITCH Filed April 2, 1930 s Sheets-Sheet 5 .Zzdezzior; M41? 771v LUTHER Patented Apr. 18, 1933 UNITED STATES PATENT OFFICE MARTIN P..LU-'1HER,. OF CHICAGO, ILLINOIS, ASSIGNOR TO SUI'ER SAFETY SWITCH C0 .11

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS ELECTRIC SWITCH Application filed April 2, 1930.. Serial No. 440,992.

My present invention relates to switches and particularly to those known as the multiple type and in which a plurality of circuits are opened or closed by a movement of a common operating mechanism and handle.

One of the principal objects of my invention is to provide a switch and switch operating mechanism that is possessed of a high degree of safet readily remove or replaced without the danger present in switches which are now available. The present structure is arranged in such manner that it is impossible to touch any of the live parts of the switch when the door or cover is open, but in addition to this factor the disposition of the parts is such that in the event the cover or door should be accidentally or inadvertently opened or be removed the live parts of the switch are protected in such manner that it will be difiicult, if not impossible, for a person to become harmed.

I have also provided substantial insulation within the box bet-ween the switch parts and the walls of the box that completely insulate this structure and in addition thereto insure against fire due to a sparking or arcing of the contact members when being pulled apart. This prevents the current flashing through the housing or box during an operation of the switch.

In addition to the foregoing it is an object of my present invention to provide a switch box and switch parts, the arrangement of which is such that an area of considerable extent is provided to accommodate the wiring, and the parts of the switch and their operating mechanism is so compact that they occupy only a small space, thus permitting of a reduction of the dimensions of the switch box or housing.

I have also provided a novel manner of supporting and insulating the stationary and movable parts of the switch, the construction and arrangement of which is such that it is not necessary to provide a boX or housing of unusual or special shape and thus permits the use of the enclosure of a true rectangular form.

In the arrangement heretofore mentioned I have mounted the terminals and the stawhereby the fuses may betionary members of the switch close to the.

sides and back of the housing or box which permits the intervening space to be occupied by conductors or wires, and also allows the ordinary fuses being placed in approximately a horizontal position and extending across;

the box where they are convenient to handle. After an understanding of my invention is had it will be obvious that numerous other objects and advantages are incorporated in the structure. I prefer to carry out my invention and to accomplish the numerous objects thereof in substantially the manner- 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a fragmentary section taken on line 33 of Figure 1 and lookin in the direction of the arrows, the parts 0 the switch being opened, and,

Figure 4 is a view similar to Figure 3 except that the parts of the switch are shown closed.

Figure 5 is a transverse section taken on line 55 of Figure 2 and drawn to a larger scale to illustrate the formation and mounting of the ope-rating bar and one of the insulating housings for the stationary contact element.

Figure 6 is a section on line 6 of Figure 2 looking in the direction of the arrows and showing the parts illustrated in Figure 5 in vertical section.

Figure 7 is a sectional View of the operating bar and showing one of the movable contacts and a fuse-carrying clip or yoke.

The drawings, it will be understood, are more Or less schematic and are intended to disclose a typical or preferred embodiment of my invention, and in said drawings I have employed similar reference characters to designate like parts whereby they occur throughout the various figures.

As heretofore stated, my switch is of the inclosed or housed type and is therefore enclosed within a sheet metal box. This box consists of longitudinally disposed parallel side walls 10 and 11 that are connected at eral flanges 16 along its'edges that overlap the,

edges of the box,-and said cover is mounted upon the longitudinal wall 11 by means of hinges 17 A transverse spring plate 18 is secured to the wall 10 and enters a slot in the adjacent portion of the door when the latter is closed. This plate is provided with a latching spur 19 to release'the cover or door or tomaintain it in closed position and this plate is also provided with an aperture 20 through which a padlock or the like may be inserted to lock the door. The spring latch, however, is not the-sole means for maintaining the door inclosed position for the reason that I have provided a novelhandle for operating the switch which will later be described and which maintains the door shut so long as the parts of the switch are closed.

The innerfaceswof the longitudinal walls and the back or rear wall are respectively provided with sheets 10 311 and 14 of insulating material, which sheets are also fire proof sothat the arcing or sparking incident to'the making or breaking of contact between the switch elements is not liable to ignite v portions of the structure within the housing or box or adjacent thereto. I

i As will be seen in the drawings, the nonmovable parts of the switch are mounted adjacent the juncture between the back wall and the longitudinal walls 10 and 11. In this connection I provide a plurality of supporting bases which are shown in detail in the drawings. Each base consists of an attaching plate member 21 which is secured to the back wall 14 of the box by screws, rivets or, otherwise, and it has a laterally disposed portion 22 that is bifurcated in order to provide a guide slot 23 in which a reciprocating bar is guided as will hereinafter more fully appear. The fixed contacts of the switch are mounted upon the outer edge of the laterally disposed portion and each consists of anL-shaped piece of metal the larger farm 24 of which bridges the recess or guide slot 23 and is seated in the groove 25 in the outer I edge of the lateral member of the base. This contact element is secured to the supporting base by means of nuts and bolts 26 and its laterally disposed, arm 27 is positioned near the Wall of the'box.

the adjacent side wall 10 (or 11) of the icons ing or box and provides the switch tongue or blade that is engaged by the movable element of the switch. The slot 23 which bifurcates the supporting base is thus bridged by the stationary or fixed contact member of the switch. I

The conductor wire 28 is connected'to the long arm 24 of the fixed switch member by --means of a terminal element having a tubular end portion 29 into which the wire conductor is inserted and held, and also has a dent when the housing or box is opened, I

have provided a protector for said parts which consists of a shell cast from bakelite or other insulating substance. The protector, consists of amain portion3l of concavo-convex cross-section that arches the arm 24 of the fixed contact and its securing boltsand nuts 26' as well as the fiatlateral portion of the terminaL- At one end, preferably the end next the tongue or blade, the shell or protector has a laterally extended portion that is likewise concavo-convex in section and extends along the side of the base and encloses the tubular portion 30 of the terminal as well as the adjacent portion of the conductor wire 28 in the manner shown in Figs; 5 and 6. At the other end ofthe protector the shell has an extension 33 that projects inthe opposite direction to the extension 32 and is of rectangular shape in section'and' slightly wider than the other portions of the protector so that it encloses the tongue 27 of the contact and fits against One side wall of this extension 33 is omitted or slotted to provide an entrance aperture 34 which permitsvthe movable contact member of the switch'to enter the protector and engage the arm 27 in the manner hereinafter described.

The protector is secured in position by means of a cap screw having an insulation head 35 and the shank 36 of which passes through an aperture v37 in the protectorv and is interiorly threaded so asto screw upon inspecting or replacing any of the parts,

guarded thereby. In order however that the live parts of the switch may be tested without removing the protector I provide a hole 38 through which a proper instrument can be inserted whenever desired to make a reading.

' The-,movable; members of the switch are mounted: upon elongated bars 3.9 that are-am ranged parallel to each other andaa're" of rectangular section so that they: wiih fit into and beaguided by; the slots; on bifurcations 23 imthe bases, as shownin and 6.. It willibe seen that a. plurality ot: the bases are monnteduponthehaclcwall: of the box alongside; the adjacent side walls and; the liars, (preferably two) ,i are. mountedcloseto: saidside wallsim the-basesxthatsuppnrt; the sta: tionany: elements; on the: switch.-

The: bars are recipnocated bysuitable means, to be hereinafter described, so that they. 7 move; simultaneously whenever the switch is operated. Notches 40 are formed inthe outer surfaces of thebars: 3.9 to. re ceive the L-shaped. metal, bracket plates; .41 eachrozt which is L-shaped: andhas its lateral member 42, disposed alongside the. respective side wallsv of the housing, These lateral members each carries apair: ofspring ton.- guns"v .43 disposed parallel to each other and laterally to the bracket plate 41 and are: each slitted longitudinally. toincrease their resiliency. These. springtongues extendiifrom their mounting plates or brackets inthe di-' rection; towards the, adjacent. or fixed contact blades 27, and the slotted portions 34 of the protectors or guards, and when, the, bars are moved in the. proper direction thesetongues 4:3;willenter the recesses .34 and slide into engagement. with the; blades. 27 of. the. Stationary switch contacts thus closing the switch.

Secured upon the: plateslof the brackets are springyokes or U-shaped' clips; that 1 are secured to the platesby the. same. means that connect the brackets. to the bars: and they are in contact with said brackets .sothatwhen the fuses 45 are. placed in these clips or-yokes thecircnit will beformed through said yoknes, the brackets, and the: tongues when the latter are in contact with the blades; 27: of the: stationary portion of the switch Thehandte 4G. is disposed upon the exterior of the housing or box. andconsists preferably of. a. piece. of heavysgauge wire that has a. portion bent laterally to the handle to provide a, spindle, 472 that; extends through the. side walls 10 and-11 0f the housingto provide the; fulcrum for. the handle,- as well as, a pivot for part oflthe, adjacent: control mechanism. A coiled contraction-spring: 48

connects the spindle with the. adjacent. end of one of the bars 39. and acts as a recoil to prevent jarring, of the bars and'switchel'ements when the partsofthe switch are moved out of contact or in a direction away from the spindle 47., a

A U-shaped oscillatory. member is mounted loosely upon the spindle 47' with the latter piercing its parallel lateral arms 49 and with its. mainportion 5Qlying parallel with said spindle, andthe ends of the arms49 are con- 51; withthe. adjacent ends of thegbans The .mechanism tor moving the Urshaped. membenzet -tt); consists of. a casting of "inregulamzshape: thatis bored.- axi-ally to receive the spindle t'I andyat; its outer portiomisprovided with a notch or recess 52in which the angle: formed by thespindl'eand handle-.ispositioned. 1 The. outer portion. 53 (at-this casting: is cylindrical solasto-fit into aroundopening in the walk 1 .1 of thehousingr onloox, and the. portion ofthe casting within. thexbox isconical' shaped as: at 54 with its; base innermost, while projecting from tlmbasezoi-the cone-shaped portion is; a. pair of oppositely. disposed parallel lugs 55. Thesezlugs: are positioned to; engage opposite edgesof the adjacent arm=49and the-adjacent endofthe body: portion of thefU-shaped element when the structure is operated: bythe handle. When the handle is. moved from oneipositionz to another these lugs will en gage the operating member in the manner shown: in 311ml 4 ofthe drawings and wilhrock the U-shaped membercausing the reciprocation. of the bars 39'.

Inorder to create. tension as well as to insure the absolute. make breakof the switchelements. I have provided the. mechanism'which will now be. described- Inter mediate. the lugs; 55 the casting is provided with ears 5t between which is hinged a lug 57:1;0 which a disk 58 issecured, and. a plunger rod 59r projects. fromsaid disk. The opposite end of the plunger rod passes. through an aperture 60 in the lateral-member 61 of an L-shaped bracket: 62 that is secured to the. adjacent portion of the housing wall'll. Interposed between i lateral member- 61 and the disk 58-, and surrounding the plunger red-:59, is a'heavy coiled expansion. spring 63'. When the plunger rod 59 is upon either side ofthe plane intersecting the spindle- 47 and the aperture. 60 the spring will push against the. disk and will cause the ear 56 to be moved in one direction or the other, tlrm. forcing the lugs 55' against. the proper portions of the U-shaped operating memher and moving the bars 39. in one direction or the other. In Figure 3-015 the drawings thespring 63 is: shown as expanded and the ear 56pis below the plane intersecting the spindle 4'1 and: theaperture 60, and'themovable parts of: the switch are out of contact with thefixed parts. In Fig. 4 the spring Git-is shown contracted and in the position just at the time it is exerting its. full power, which will maintain the switch parts in. positive contact after they have been moved into engagement. Thus: it will be apparent that the switch parts are maintained in theirpositionsby means of the spring 63 and its contactingparts are in either a fully opened or'a fully closed position, and it is practieall'y impossible to stop. the movement of the parts at: an intermediate point. Because of thelfactthe U-shaped operating member. is loose on the spindle 47 and there is a slight play or looseness between the handle and the notch or recess 52, the action of the spring 63 causes a rapid snapping of the switch when being either opened or closed, thus making a quick contact or brake.

In order to maintain the door 15 against being opened while the parts of the switch are in on position, the outer end of the handle has a lateral outwardly bent portion 64, which at its end is bent downwardly and oblique to provide a grip member 65. On the adjacent edge of the door I secure'an abutment element orstop 66 in the form of a metal casting that is arched or slotted'between its ends as seen in detail in Figs. v1, 3 and 4. The handle, portion 46 is positioned and operates adjacent the wall 11 of the box and the hinged edge of the doorand when the grip-member 65 of the handle is in a depressed position (Fig. l) for the on position .of the switch parts the handle portion 46 will lie against and in the path of movement of the abutment or stop 66. so. that the door may not be opened. When,however, the grip and handle have been moved to the position shownin Fig. 3 for the 0E position of the switch the handle 46 will: be out of the path of m'ovementof the abutment and the lateralportion64 will offset the grip 65 far enoughfrom the box wall to permit the door tobe opened and'the abutment to clear the handle;

..-WhatIclaim is:-' a

1-. An electricswitch comprising a support, insulating'guides mounted thereon,fixed terminals carried by said guides and having contact blades, an apertured insulating housing enclosing each terminal and blade,reciprocable members mounted in said guides, movable contacts carried'by said members andcoactable with said blades through. the apertures in said housing, and means for moving said members simultaneously.- I

2. An electric switch comprising asupport, insulating guides thereon, fixed terminals carried-by said guides, contact blades extending from said terminals, an aperturedinsulating housing enclosing each terminal and blade,

' sliding bars reciprocable in said guides, m0va= ble contacts mounted on said bars, means for simultaneously moving said bars to cause said contacts to enter the housing apertures and engage said blades, and conducting elements connecting the contacts on one bar with cor responding contacts upon another bar.

3; An electric'switch comprising a support, two rows of alined guide structures secured thereto and having apertures, reciprocable parallel bars slidably mountedin said guides, terminals enclosed in said guides, contact blades extended from said terminals and accessible through said apertures, contacts mounted on said bars, and common means for moving said-bars, whereby to cause said contacts'to enter said apertures and engage said blades. m

4; An electric switch comprising a support,

two'rows of alined guide structures secure theretdand having apertures, reciprocable parallel bars slidably mounted in said guides, terminals enclosed in said guides, contact blades'extended from said terminals and accessible through said apertures, contacts 2 i mounted on said bars, common means for moving sald bars, whereby to cause said contacts to enter said apertures and'engage said blades, and'removable conductors forming bridges between the contacts on the respective actable with the contacts on the respective bases, means operatively connecting said bars, and devices for moving said bars simultaneously. a 1

" 6. An electric switch comprising a support,

a base thereon having a guideway, a switch contactmounted on said base, a conductor terminal also mounted on said base, an in sulating guard covering and protecting said contact and terminal and provided withv an aperture adjacent the contacts, abar slidable in said guideway, and a switch contact carried by said bar and adapted, when moved therewith, to enter said aperture and engage the first-mentioned contact. I

thereon adjacent'the longitudinal walls of the housingand each havingna guideway, spaced slidable bars reciprocable in the respective .guideways adjacent the respective walls a conductor terminal and switch contact mounted oneach base, a-fuse-clip and switch contact mounted on each bar, and means for reciprocatlng saidbars simultane- 8. An electric switch comprising a support,

bars simultanously, and "insulating guards.

covering and protecting the structures mounted on the respectlvebases. P

9. An electric switch comprising a rectangular housing, a plurality of fixed and movable contacts therein, a pair of spaced reciprocableparallel bars adj acent-the longitudinal walls of-saidhousing and to which said movable contacts are secured, andaplu- 7 An electric' switch comprising a rec tangular housing, a pair of bases mounted rality of bases secured in the housing adjacent the longitudinal Walls thereof in which bases said bars are slidably mounted and one of said fixed contacts secured to each base.

10. An electric switch comprising a support, fixed and movable contacts thereon, reciprocable bars to which said movable contacts are secured, and bifurcated bases arranged in spaced relation on said support, said fixed contacts bridging the bifurcations thereof and said bars guided in said bifurcations.

Signed at Chicago, in the county of Cook and State of Illinois, this 28th day of February, 1930.

MARTIN P. LUTHER. 

